I have had two acquaintances die in the past week from suicides. They lived far apart and did not know each other. Phil Donahue is quoted as saying "suicide is a permanent solution to a temporary problem." In the first incident, the problem . . one of health . . did not seem to be a temporary problem. In the second I just don't know. The reason seems unclear. Friends of both of the individuals all said the same things: the victim was the last person in the world one would have thought of killing themself.
I think many, many people are like the classic description of a duck: serene on the surface but paddling like hell underneath. Too many people seem to keep their troubles to themselves until they feel they just can't deal with them any more. And so they take the final step.
It is not for we survivors to judge them. We are left with trying to understand the victims and their motives. It is a difficult and nearly insurmountable task.